The difference between this kind of thing is that the Haptek Player animates as it goes along, ie, it's a 'Realtime' rendering - whereas DAZ3D is a more finished 'set-piece' animation - like a movie or short clip.
So take for example the Happy mood in Hal - it can vary a bit and goes through variations and it moves parts of the body around. But if you had a 'happy' film-clip instead, you'd see the same repeated clip again and again or at different times (perhaps - depending on how well spliced or varied the movie is).
Think of it like the difference between a flag billowing in the wind, and a repeating loop of film showing a flag billowing in the wind.
The other thing is the DAZ stuff is more artistic-oriented and photorealistic. I guess when we all have even faster graphics cards the quality of the two fields won't look so far apart - the time it takes now though to render a single flat DAZ image tells you that their technology would be too slow to get the kind of real-life feel that the Haptek heads give on anything other than the fastest PC's.
On that last point even if you could it would still need further development to be like a Haptek type system - as it is though theres no reason why you cant use Daz to make a series of animations and play them back as wanted in a program like Hal - I think that's basically how MSAgents work and is already being done using programs like DAZ.
Probably the most direct way is to make a series of your own animations and have hal run them on demand in any kind of player that will play things like avi and mpg - the kind of files programs like DAZ produce as an end result.
As Hal can run external programs it's not really limited to just Haptek and MSAgent, someone industrious enough could create any kind of playback animation - even using film of real people. For more on that try the Virtual Humans site, I saw some links there this week to work by someone making characters that really are hard to tell from a real person - basically because they are a real person - just that he seemed to be using clever and blended playback of footage of an actual person.
I hope that made sense, I tried to answer as best I could.